Radiator fin



Dec. H, 1934. H. .J. KRACKOWEZE RADIATOR FIN Filed May 10, 1935 IN VEN T OR.'

A TTORNEYS.

Patented Dec. 11, 19 34 UNITED STATES RADIATOR FIN Hermann J. Krackowizer, Chicago, Ill., assignor to Refrigeration Appliances, Inc., Chicago, Ill.

Application May 10, 1933, Serial No. 670,338 2 Claims. (01. 257-262) This invention relates to radiators, and particularly to radiators having plate fins to increase the radiating surfaces of tubes in which flows the fluid to be heated or cooled. 5 The object of the invention is to provide an improvement in the construction of the plate fins which have spacer lugs formed integrally with the fins and punched therefrom on three sides, leaving one side uncut, and the lug bent at right angles to the fin to space the plate fins apart when assembled upon tubes. These lugs, as heretofore constructed, as shown for example in the patent to Seward No. 1,873,052, have been in a trapezoidal shape, the longest side of the trapezoid being at the outer end of the lug and the smaller end of the trapezoid being attached to the fin plate. This construction prevented the trapezoidal lug passing into the space made by bending the lug at right angles to the fin. This construction reduces the contact area between the lug and the adjoining fin plate. Furthermore,

the smaller end of the trapezoid is closest to the part of the fin plate from which it radiates, causing choking of the heat from the plate to the lug. After assembling the plate fins on the tubes, it being heretofore the practice to expand the tube outward to make a tight fit, the lugs had a tendency to bend out of shape because they were structurally weak or narrowest at the point of maximum strain.

In these heretofore constructed lugs and plates, the lugs straddled the holes and when hot dipping or electroplating with metal in the heretofore constructed trapezoidal lugs which straddle a hole, the coating metal does not join a lug and an adjacent plate except in two small spots which was a disadvantage and ordinarily the heretofore constructed lugged fin plate did not extend from one row of tubes to the next and this necessitated a gap between the plates on each tube which further resulted in cutting down the radiating area by the sides of this gap. This gap was found to be disadvantageous for several reasons. For example, condensation accumulated in the gaps instead of running off and when the condensation gathered in the gaps it frequently turned to ice which gradually spread over the radiating surfaces and formed in such thick masses as to greatly reduce the circulation of air so vital in air cooled radiators.

The advantage of having the plates extend over a plurality of tubes instead of one resulted from the fact that when each plate is pushed on only one tube the plate tended to rotate on the tube when hot dipped and this gave the finished radiator a poor appearance.

To overcome the difiiculties heretofore encountered in radiators of this character, applicant has extended his plate over a plurality of tubes and has cut and punched his lugs from the plate as will now be more fully described in connection with the attached drawing in which:

Figure 1 represents a plate with the lugs cut and punched therefrom.

Figure 2 shows the plates put on a plurality of tubes.

Figure 3 shows the position of the cut out lugs when the plate is turned at from the position shown in Figure 1.

Figure 4 shows the plates on the lugs when half the plates in one series are turned at 180 to the plates in the other series.

1 represents a plate and 2 a series of lugs cut and punched therefrom. These lugs are cut by a dye in the ordinary way.

When a plate 1 (Fig. 3) has its lugs 2', 2' cut by the same dye, if the plate 1 was placed above the plate 1', the lugs 2 being smaller at their outer end would pass into the cut out opening of the adjacent fin, but by cutting and stamping the lugs in plate 1 unsymmetrically and then turning the plate through 180 so that a notch 5, for example in plate 1 would be in the position shown in Figure 1, the corresponding notch 5' (Figure 3) would be in the position shown therein. Then when the plates are put on the tubes, as shown in Figures 2 and 4, the lugs 2 between the plates would bear on a solid part of the plate and not coincide with the openings in the plates. The notches 5, 5 conveniently guide the assembler in placing the plates one over the other since the cut out notches 5, 5' would be arranged as shown in Figure 4 and when so arranged the smaller end of each lug would contact with the solid portion of the plate. The tube 6, furthermore, would prevent anyrotation of the plates around any tubes and with the smaller ends of the lugs bearing against the solid portion of the plates when the plates and lugs are assembled as shown in the drawing, my radiator has the maximum strength and the maximum radiating qualities.

It will be observed also that when the plates are assembled on the tube 6, it is desirable that the holes in the plates be not in alignment. The hole in one plate being out of line with the hole in the next plate will cause a tortuous line of circulation through the plates which, of course, is advantageous.

punciimgeui the 3115s in both series oi? pistes he same dye am], men displacing the lugs rise is these m? the ether turn 6 21111521 32%" relative to the ether piste series 1311s imies and lugs siiis 1V3 M is stile? and proriuee a gemexiic. This communitie e hettom 0f the lug where i; is: than the eutermosis end. the l U irls the flaw sf heat as mmpereci witi 1113, where the small and m. the has is the pi e am furthemsre, puts a, seetime: 01 the lug at a, point a? maximum strain when amassing the tube to make a, tight fit in e. feels and by having each lug abutting saiid part sf 3 :33: when the entire censtruction is seated with metal, the metal will form a fillet on each side 02 every lug where is iouches an adjoining fin plate. This fillet increases the radiating surface as sens pared to the construction where a lug straddles a. hole in the piste.

Having now described my invention and the W enner which the pistes are punched? and the s (I placed burning the pisses through ass pistes are placed on a gsiumiiiy of tubes,

as as is:--

or element izieluding a, pimmiity of tubes anal. pistes exilenciing around at iessi We mines each plate having winches out iugs and 321s lugs izeing unsymmetricaiiy arranged an either Ensiff e2 ysiste whereby when said pieie is tamed 18V and fitted to its adjacent piste, the punched out Rugs wiili each Iss4. against and be severed by the saiid part of its adjacent pisfize, said lugs being xm'rmwer at iheii' outer ends than at the ends wheze the lugs join the mate.

2. resistor including pisses and punched 011% Zugs, each lug being xmrmwer at its mater emit shim where joins the plates, the lugs an adjacent pistes being unsymmetricaiiy arranged s0 that when the pistes are assembled each lug wiii coniaeet and be severed by a solid yortion of the sdjs= sens piste.

smzesmsm J. KRACKOWEZER. 

